Merge pull request #400 from sfPlayer1/master

Fix various registry issues
I am not modding, I am fixing an annoyance. The MCP version has long since been 9.03. Also, the JSON from MC updated..
I'm still not modding. Player has contributed greatly to the 1.7 release of FML. He needs authorship credit.
Fix vanilla bug causing integrated server saving from 2 threads concurrently after a crash
Registry: Fix Block-before-ItemBlock allocation when loading 1.6 world saves, more validation
prevent the world from getting saved twice at shutdown
Registry: Crash earlier with conflicting name/object registrations.
Registry: Misc tweaks